Researchers studying coyote and wolf interactions in Yellowstone National Park have published results in the Canadian Journal of Zoology.

In "Interference competition between gray wolves and coyotes in Yellowstone National Park," J. Merkle, D. Stahler and D. Smith write in the abstract:

"Factors influencing the outcome of interspecific interactions between sympatric carnivores, along with population-level consequences, are not clearly understood. The reintroduction of gray wolves (Canis lupus L., 1758) to Yellowstone National Park provides a rare opportunity to study interactions with coyotes (Canis latrans Say, 1823), which had lived in the absence of wolves for >60 years.

"We evaluated direct interactions between wolves and coyotes to identify factors influencing the outcomes of interspecific interactions and describe the context and degree of competition and coexistence. Using radio-collared wolves, we documented 337 wolf - coyote interactions from 1995 to 2007.